Making black dipping slip from throwing scraps

I've been saving my throwing scraps and slip in a bucket with the intent of making a dipping slip (occasionally I'll use a hand blender to smooth it out). I use Highwater Little Loafers fired to cone 5 and was told the easiest way to make slip was to just use the clay body you throw with. The part I'm trying to figure out now is how to color the slip so that it fires black and looks black when covered with a clear glaze. I read on some forums that using Mason Stains could work. Has anyone used Mason Stains before to make a color dipping slip? If so, what is a good ratio to start testing out with?

Also, any suggestions on which one black stain to pick (http://www.sheffield...tains-s/106.htm) based on non-toxicity and/or behavior? Still learning the chemistry side of colorants and glazes so any tips are appreciated.

You might want to start out with a ratio of 10% mason stain to the amount of dry Little Loafers; 6600 black is a good one to start with. Also consider doing a progession test . . . 2%, 5%, 7%. 10% to see how it affects colors. The key will be to sieve the stain and slip to make sure it is well blended.

Different mason stains need different amounts in slip . . . but at some point you will reach a saturation point where adding more stain does not affect the color result. So, some experimentation is encouraged. No need to add more stain (and dollars) than needed.